Load Carrier
The invention relates to a load carrier provided with a coupling device, adapted for being releasably coupled to a towing hook of a vehicle; the towing hook is provided with a neck and a ball ; the coupling device comprises a coupling housing and a clamping mechanism connected to the coupling housing, the coupling device has an open position in which the clamping mechanism is attached to the towing hook and a closed position in which the clamping mechanism clampingly encloses the neck and/or the ball of the towing hook, the clamping mechanism comprises two ball-clamping members.
Such a coupling device is known from European patent application EP1293386 for mounting a load carrier, such as a bicycle rack, onto the towing hook of a vehicle, like a passenger car. In a complicated clamping mechanism two ball-clamping members are displaced by means of levers from an open position to a closed position; which levers are extending backwards over the towing hook, as seen from the vehicle, from the front side of the coupling housing in the direction of the load carrier. This known coupling device has the disadvantage that the ball-clamping members, upon mounting onto the towing hook, are often incorrectly positioned around the ball, so that additional means are necessary, such as a device for aligning the ball-clamping members. Therefore there is a need for a coupling device which is simpler and less complicated, which has fewer components, and which is therefore cheaper to manufacture.
A load carrier for bicycles is also known from European patent application EP1799512 having a coupling device, which among others includes a camshaft. When this load carrier is to be coupled with a towing hook, firstly the bike carrier is positioned onto the ball of the towing hook, and then by tilting the load carrier and the coupling device, a camshaft is clamped against the ball-clamping element. Thereby a good, stable connection is obtained between the coupling device and the ball so that during driving the load carrier will not become lodged skew onto the towing hook or fall off the hook. These and other known load carriers have the disadvantage that mounting the load carrier onto the towing hook is complicated and difficult and that, due to wear after prolonged use, the coupling device with the camshaft clamps less well or is coupled onto or removed from the towing hook with difficulty.
It is the object of the invention to provide for a coupling device by which a load carrier can be connected reliably and quickly to a towing hook of a vehicle, without the necessity of having to slide in or tighten additional means, or whereby means are necessary for aligning the ball ball-clamping members; and whereby coupling and uncoupling can be performed by a simple lever-movement of the load carrier. In addition, the coupling device must realise a solid, stable, not moving or sliding firmly enclosure; and must be simply and cheaply manufactured and assembled so that the coupling device comprises a minimum amount of components which are easily fabricated. This object is achieved according to the invention in that both ball-clamping members are hingedly interconnected.
By hingedly mutually coupling the ball-clamping members, the ball-clamping members can be easily aligned and positioned onto the ball during mounting thereon in the opened position of the coupling device ensuring that a good and stable enclosure is obtained and, as a result thereof, that a firmly attachment is obtained on the towing hook in the closed position of the coupling device.
Preferably a hinge is provided between the two ball-clamping members.
With this hinge, the ball-clamping members can be reliably and easily moved apart from each another to the open position of the coupling device, and exert a high clamping force over a large surface of the ball of the towing hook in order to prevent moving or shifting of the coupling device upon the towing hook during driving of the vehicle. In particular the hinge is formed by a projecting transverse ridge or rib on the one ball- clamping member and by a corresponding transverse groove on the other ball-clamping member.
These measures will provide for an easy to manufacture hinge, which can be easily applied to the two ball-clamping members. Moreover, such a hinge can be easily disassembled for mounting or dismounting by sliding or moving the transverse rib in or out of the groove.
More in particular the transverse rib and the transverse groove constitute a detachable hinge.
This has the advantage that each of the ball-clamping members can be manufactured separately and can be mounted easily in the clamping mechanism.
Preferably the one ball-clamping member is provided with an overlapping section, which extends at least partially over the other ball-clamping member.
Thereby a good, stable and firmly all-around grip is obtained with the towing hook, because the overlapping section of the one ball-clamping member fixedly presses the section of the other ball-clamping member, which is positioned under said overlapping section, against the towing hook and the ball positioned thereon, thereby preventing shifting of the coupling device and the load carrier.
In an advantageous embodiment the first ball-clamping member is provided with a stop, which is adapted to the shape of the neck of the towing hook.
As a result the coupling device is supported by the underside of the neck of the towing hook, so that the clamping force on the towing hook is increased, shifting of the coupling mechanism is hampered and also the downward directed tilting force or force of moment of the weight of the load carrier is counteracted.
Particularly the first ball-clamping member is provided with a ball-clamping section, which is adapted to the shape of the ball of the towing hook.
Thereby a better contact is achieved between the ball-clamping member and the ball, so that the coupling device is more firmly and fixedly clamped onto the ball, so that displacement over the ball is prevented, during its use on a towing hook of a vehicle. Preferably the clamping mechanism comprises:
- the first ball-clamping member which is pivotally mounted onto a first pivot axis;
- the second ball-clamping member, which is pivotally mounted on a third pivot axis,
- two levers being fixedly interconnected with their first ends to a second pivot axis and with their second ends to the third pivot axis;
such that the ball-clamping members hinge relative to each other.
By means of this lever system, having two coupled force-transmitting levers, the ball- clamping members are mutually pivotally moved relative to each other. The clamping mechanism consists of three interconnected axes whereby the second ball-clamping
member is eccentrically moved around the second pivot axis, when the coupling housing is tilted downward from the open to the closed position. The lever system locks the coupled ball-clamping members within the clamping mechanism and moves the pivotally coupled ball-clamping members apart from each other in the open position of the coupling device and moves the coupled ball-clamping members towards each other in the closed position of the coupling device.
In particular the first and the second pivot axis are mounted rotatably to the coupling housing such, that the levers, in coupled closed position of the coupling device on the towing hook, are extending forwards over the towing hook, from the load carrier in the direction of the vehicle.
This allows for a compact design of the coupling device, because the coupling housing does not extend across the towing hook and may therefore be provided of small dimensions. Also, the transmission of force between the load carrier and the clamping mechanism is more direct, allowing for obtaining a better clamping effect.
Preferably the coupling housing is provided with two sidewall sections, both of which are provided with means intended to receive the ends of the first and the second pivot axis; wherein the coupling device is coupled with the towing hook by positioning the open coupling device with its first and second ball-clamping member onto the ball and subsequently by tilting the coupling housing around the first pivot axis to the closed position of the coupling device, wherein the second ball-clamping member firmly clamps around the ball by the levers, which move eccentrically relative to the first pivot axis, and which pivot around the second pivot axis.
By the use of sidewall sections, the pivot axes can be rotatably attached or bearing- mounted to the coupling housing.
In a further embodiment the movement of the second pivot axis around the first pivot axis is a circular path, when opening or closing of the coupling device. This is achieved by including both the first and the second pivot axis rotatingly in the coupling housing and/or the sidewall sections.
In particular the coupling housing is fixedly connected to the load carrier, so that the load carrier operates as a lever in order to apply the clamping force on the ball-clamping
members of the coupling device. A separate latch or lever is therefore not needed for fixedly clamping the load carrier onto the towing hook.
A further embodiment is characterized in that the first ball-clamping member is provided with a stop for the neck of the towing hook. By supporting the coupling device onto the neck, the stability of the load carrier on the towing hook is increased.
Preferably the second ball-clamping member partially overlaps the first ball-clamping member. This allows the clamping forces to be better distributed over the entire contact area between the two ball-clamping members and the ball of the towing hook.
Preferably the first ball-clamping member is provided with a ball-clamping section, which is adapted to the shape of the ball of the towing hook.
Therefore the second ball-clamping member is having a larger friction surface with the ball, so that rotation of the load carrier onto the towing hook is prevented.
Particularly the coupling device is provided with a locking member which engages a locking means mounted on the first ball-clamping member to lock the coupling device in the closed position. By this measure a highly road traffic safe coupling device is obtained, whereby the risk of undesired detachment from the towing hook, for example while driving, is greatly reduced.
The invention is hereafter further explained by means of some embodiments with reference to a few drawings.
Fig. 1 shows a perspective view of the coupling device according to the invention, Fig. 2A shows a perspective view of the coupling device in open position,
Fig. 2B shows the coupling device of Fig.2A in a half closed position,
Fig. 2C shows the coupling device of Fig.2A in closed position,
Fig. 3A shows a side view of the coupling device in open position,
Fig. 3B shows the coupling device of Fig .3A in a half closed position,
Fig. 3C shows the coupling device of Fig.3A in closed position,
Fig.4 shows in detail the first and the second ball-clamping member.
In Fig.l is shown a perspective view of the coupling device 10 according to the invention. In the embodiment displayed, the coupling device 10 is shown in closed position. Part of the ball 27 of the towing hook 25 is just visible between the first ball- clamping member 14 and the second ball-clamp member 20. In this embodiment the second ball-clamping member 20 is pivotally attached to the levers 18a, 18b by means of the third pivot axis 19. By means of the second pivot axis 17 the other ends of the levers 18a, 18b are pivotally connected to sidewall sections 12a, 12b (see Fig.2A) of the housing 11. The sidewall parts 12a, 12b are provided with means 16a, 16b (see Fig.2A) such as openings, axel stubs or retaining rings 4, for receiving the second pivot axis 17 and the first pivot axis 15. In Fig.2A is shown that the first ball-clamping member 14 is pivotally connected to the sidewall sections 12a, 12b by means of the first pivot shaft 15. These sidewall sections may be detachable parts or may be part of the coupling housing 11. The two levers 18a, 18b, the third pivot axis 19 and the second pivot axis 17 are fixedly interconnected, so that a strong and sturdy clamping assembly 9 is formed in which the second ball-clamping member 20 is pivotally mounted. The levers 18a, 18b extend forwards, in the closed position of the coupling device 10 in Fig. l, over the towing hook 25, from the load carrier and the coupling housing 11 in the direction of the vehicle (not shown). The entire coupling device is preferably fixedly attached to the load carrier so that by tilting up and down of the load carrier the coupling housing 11 is tilting simultaneously. In this embodiment the load carrier may advantageously be used as a lever. If desired, clamping force on the ball-clamping members is created with a separate lever.
Fig.2A, 2B and 2C show how the coupling device 10 is affixed on the ball 27 (Fig.l) of the towing hook 25. This is done by tilting the coupling housing 11 relative to the towing hook 25. In Fig.2A the coupling device 10 is in the open position, wherein the levers 18a, 18b and the second ball-clamping member 20 have an upward directed position. Therefore the first ball-clamping member 14 and the second ball-clamping member 20 are positioned at a distance from each other so that the ball of the towing hook can be easily introduced between the two clamping members.
In Fig.2B, the coupling device 10 is approximately half closed so that both ball- clamping members are displaced towards each other by the eccentric motion of the third pivot axis 19 around the first pivot axis 15.
In Fig.2C, the coupling device 10 is fully closed and exerts a high clamping force with both ball-clamping members, using the levers 18a, 18b, on the ball and the neck of the towing hook.
In Fig.3A, 3B, 3C placing and clamping the coupling device 10 is once more shown from a side view; for clarity lever 18b is omitted and not visible. In this embodiment is clearly shown that the first ball-clamping member 14 and the second ball-clamping member 20 are mutually hingedly coupled. The hinge 8 is positioned on top of the first ball-clamping member 14 so that the first and the second ball-clamping member partially overlap each other. The coupling device 10 is positioned in an upward direction so that the distance between the second pivot axis 17 and the first pivot axis 15, relatively as seen from the third pivot axis 19, is mainly a difference in height, so that the levers 18a, 18b move the second ball-clamping member 20 outwards through the hinge 8 thereby releasing space 3 between the ball-clamping members for placement upon a ball. The coupling housing 11 and its fixedly connected sidewall sections 12a, 12b can now be moved downwards via the curved path A so that the third pivot axis 19 will follow an eccentric arcuate path B around the first pivot axis 15. By this movement the distance between the third pivot axis 19 and the first pivot axis 15 shortens, causing the ball- clamping members to be moved toward each other about the hinge 8, and thereby letting the space 3 disappear between the ball-clamping members.
In Fig.3B, the coupling device 10 is about half closed so that the third pivot axis 19 through the levers 18a, 18b (removed in the figure) has been displaced in the direction of the first pivot axis 15 and the second ball-clamping member 20 is displaced to the first pivot axis 15 and the ball first clamping member 14 in the direction of arrow C. The ball-clamping members are pressed together in this way, resulting in the disappearance of the space between the two members.
In Fig.3C the coupling device 10 is fully closed and the third pivot axis 19 is positioned substantially in line with the first 15 and second 17 pivot axis so that via the levers 18a, 18b (not visible in figure) the second ball-clamping member 20 has dispaced maximally to the first ball-clamping member 14, so that they exert together a maximum clamping force on the ball of the towing hook.
The movement of the second pivot axis 17 is in this embodiment a circular path around the centre of rotation of the first pivot axis 15.
In Fig.3B also a lockable embodiment of the coupling device 11 is shown. The coupling device is locked in its closed position by a locking member cooperating with locking means; in this embodiment a locking member 35, which extends into the coupling housing 11 and which lockingly snaps into the recess under the locking ridge 36 affixed to the first ball-clamping member 14.
First ball-clamping member 14 is in an advantageous embodiment provided with a stop 21, as shown in Fig. l. The stop is provided with a shape corresponding to the shape of the neck of the towing hook, so that the coupling device 10 is also supported on the neck to increase the stability. By means of the stop 21 the coupling device 10 is supported by the bottom side of the neck 26 of the towing hook 25, so that thereby moving, shifting or tilting, parallel to the levers 18a, 18b, is prevented of the coupling device 10 over ball due to the downward tilting force or moment of the weight of the load carrier.
In the use position the second ball-clamping member 20 extends over the first ball-clamping member 14, so that over a large surface area of both ball-clamping members the clamping force can be transferred. Both ball-clamping members are preferably hingedly linked together so they can be moved apart or tilted apart into the open position allowing for inserting or removing the ball in and out of the coupling device. The first ball-clamping member 20 may be provided with a ball-clamping section 22 which is adapted to the shape of the ball 27 of the towing hook.
In fig.4A and 4B the hingedly coupled ball-clamping members 14, 20 are shown in more detail. Fig.4a shows the first ball-clamping member 14 provided with the stop 21. The first ball-clamping member 14 is on its upper side provided with a transverse groove 6 to form a hinge with the second ball-clamping member 20. Fig.4B shows the second ball-clamping member 20 with a projecting transverse rib 7. By inserting the transverse rib 7 into the transverse groove 6 a hinge is formed so that both ball-clamping members are hingedly linked to one another. Preferably, a releasable hinge is formed wherein the transverse rib 7 can be moved easily in and out of the transverse groove 6, for example, by sliding in the transverse direction. This has the advantage that each ball-clamping member can be manufactured separately and can be mounted easily into the clamping mechanism.
The ball-clamping members 14, 20 are preferably provided with an overlapping section 5 so that a firmly all around grip is obtained over the entire contact area between the ball- clamping members and the ball of the towing hook, because the overlapping section 5' of the superimposed ball-clamping member 20 presses fixedly the section 5" of the ball- clamping member, which is subjacently positioned under the overlapping section 5', against the towing hook and the ball fitted thereto.